2/19/04 Pilot/Controller Glossary
PCG D−1
D
DA [ICAO]−
(See ICAO Term DECISION
ALTITUDE/DECISION HEIGHT.)
DAIR−
(See DIRECT ALTITUDE AND IDENTITY
READOUT.)
DANGER AREA [ICAO]− An airspace of defined
dimensions within which activities dangerous to the
flight of aircraft may exist at specified times.
Note: The term “Danger Area” is not used in
reference to areas within the United States or any
of its possessions or territories.
DAS−
(See DELAY ASSIGNMENT.)
DATA BLOCK−
(See ALPHANUMERIC DISPLAY.)
DEAD RECKONING− Dead reckoning, as applied
to flying, is the navigation of an airplane solely by
means of computations based on airspeed, course,
heading, wind direction, and speed, groundspeed,
and elapsed time.
DECISION ALTITUDE/DECISION HEIGHT
[ICAO]− A specified altitude or height (A/H) in the
precision approach at which a missed approach must
be initiated if the required visual reference to
continue the approach has not been established.
Note 1: Decision altitude [DA] is referenced to
mean sea level [MSL] and decision height [DH] is
referenced to the threshold elevation.
Note 2: The required visual reference means that
section of the visual aids or of the approach area
which should have been in view for sufficient time
for the pilot to have made an assessment of the
aircraft position and rate of change of position, in
relation to the desired flight path.
DECISION HEIGHT− With respect to the operation
of aircraft, means the height at which a decision must
be made during an ILS, MLS, or PAR instrument
approach to either continue the approach or to execute
a missed approach.
(See ICAO term DECISION
ALTITUDE/DECISION HEIGHT.)
DECODER− The device used to decipher signals
received from ATCRBS transponders to effect their
display as select codes.
(See CODES.)
(See RADAR.)
DEFENSE VISUAL FLIGHT RULES− Rules applicable
to flights within an ADIZ conducted under the
visual flight rules in 14 CFR Part 91.
(See AIR DEFENSE IDENTIFICATION ZONE.)
(Refer to 14 CFR Part 91.)
(Refer to 14 CFR Part 99.)
DELAY ASSIGNMENT (DAS)− Delays are distributed
to aircraft based on the Ground Delay Program
parameters. The delay assignment is calculated in
15−minute increments and appears as a table in
ETMS.
DELAY INDEFINITE (REASON IF KNOWN)
EXPECT FURTHER CLEARANCE (TIME)− Used
by ATC to inform a pilot when an accurate estimate
of the delay time and the reason for the delay cannot
immediately be determined; e.g., a disabled aircraft
on the runway, terminal or center area saturation,
weather below landing minimums, etc.
(See EXPECT FURTHER CLEARANCE (TIME).)
DELAY TIME− The amount of time that the arrival
must lose to cross the meter fix at the assigned meter
fix time. This is the difference between ACLT and
VTA.
DEPARTURE CENTER− The ARTCC having jurisdiction
for the airspace that generates a flight to the
impacted airport.
DEPARTURE CONTROL− A function of an approach
control facility providing air traffic control
service for departing IFR and, under certain conditions,
VFR aircraft.
(See APPROACH CONTROL FACILITY.)
(Refer to AIM.)
DEPARTURE SEQUENCING PROGRAM− A program
designed to assist in achieving a specified
interval over a common point for departures.
DEPARTURE TIME− The time an aircraft becomes
airborne.
DESCENT SPEED ADJUSTMENTS− Speed deceleration
calculations made to determine an accurate
Pilot/Controller Glossary 2/19/04
PCG D−2
VTA. These calculations start at the transition point
and use arrival speed segments to the vertex.
DESIRED COURSE−
a. True− A predetermined desired course direction
to be followed (measured in degrees from true north).
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